Cada pergunta deste Quiz é cronometrada.
True or false? Work is done when an object is moved by a force.
True or false? Work uses a different SI unit to energy.
Into which form of energy does most energy become when work is done to overcome friction?
Thermal
Electric
Sound
True or false? Gravitational potential energy is energy stored in an object because of its position in the Earth's gravitational field.
What is the gravitational potential energy of an object of 0.5kg mass if it is lifted by 3m?
1.5J
3J
15J
10.5J
What is the power developed of an object which, when lifted, gains 60J in 10s?
600W
6W
60W
True or false? Kinetic energy is the energy of an object when it is stationary.
Which of these is the correct formula for kinetic energy?
KE = 1/2 * m * v
KE = m * v
KE = 1/2 * m^2 * v
KE = m^2 * v
KE = 1/2 * m * v^2
KE = m * v^2
True or false? A system that stores energy when a vehicle brakes is known as a kinetic energy recovery system.
True or false? Momentum is a scalar quantity.
Which of these formulae is correct for calculating momentum?
p = m * v
p = m * v^2
p = m^2 * v
p = 2m * v
p = m * 2v
True or false? In a closed system, the total momentum before an event is equal to the total momentum after the event.
Trolley A, 6kg, is travelling in one direction at 4m/s. Trolley B, 7kg, is travelling in the other direction at 3m/s. The two trolleys stick together and move off. What is the velocity of the two trolleys?
2.5m/s
3m/s
3.5m/s
4m/s
True or false? In an explosion, the total momentum is zero.
True or false? If, in an explosion, two pieces of debris move apart, they will not move with equal and opposite momentum.
True or false? A front-end collision increases the momentum of the car.
What does a g-force of 2g mean?
The force applied on an object is half its weight
The force applied on an object is twice the gravitational field strength
The force applied on an object is twice its weight
True or false? If the impact time is increased, the impact force will be increased.
Which two of these features of car safety are compulsory by UK law?
Seat belts
Crumple zones
Collapsible steering wheels
Airbags
Side impact bars
True or false? Child car seats are mandatory in the UK for children younger than 12 years old or shorter than 1.35m.